Interleaved high step-up current sharing converter with coupled inductors

Abstract

An interleaved high-step-up current sharing DC–DC converter with coupled inductors is proposed in this paper. The operation principle and property of this converter are analyzed. The ripple of the input current in the proposed converter is decreased significantly by using the two-phase parallel interleaved input. The voltage gain is extended and the switch voltage stress is reduced by the coupled inductors. The leakage inductance of the coupled inductors reduces the reverse-recovery problem of the output diode, resulting in the reduction of reverse-recovery losses. As there are two interleaved phases in the proposed converter, the third winding of each coupled inductor is embedded in another phase. With this design, when the leakage inductance or duty cycle is asymmetrical, the current sharing performance is still positive. Consequently, the new topology is very suitable for applications to occasions with low voltage input and high voltage out-put, such as the fuel cell power system. Finally, the performance of this topological circuit is veri-fied by a prototype with 500 W output.